Audio not playing over computer?

Hi, today I recorded some videos on my Nikon camera, played them on the camera, and all of the audio played as I watched the videos. When I put the SD card in the computer however, and reviewed the videos from there, none of the audio is playing. I also attempted uploading to Youtube, and no audio is coming from there either. I would like to fix this problem so I can record today, help please!

Update all your drivers and delete adobe flash player and download a brand new version - but only from the official Adobe site

Cameras

Make sure your speakers are turned on.